Electrical relay



. Feb. 7. 192s'.

C; S. SNAVELY ELECTRICAL RELA! Filed April 27. 1921 4 Sheets-Sheet l Feb. 7, 1928. 1,658,578

c. s. sNAvELY ELECTRICAL RELAY a Filed April 27. 1921 4 Sheets-Sheet 2 p La, 19

c a INVENTOR.

Feb. 7,1928

1,658,578V c. s. sNAvELY ELECTRICAL RELA! Filed April 27. 1921 v 4v Sheets-Sheet 3 .6p INVENTOR,

ATTORNEY.

Feb

C. S. SNAVELY ELECTRICAL RELAY Filed April 27, 1921 4 Sheets-S et 4 C' INVENTOR.

#.v ,-nToR/VEY.

4 for attaching the magnet cores to the top as shown at 19a. Each core is held in place' Patented Feb. 7, 1928. y A p 1 UNITED STATES .PATENT oFFlcE.

CLARENCE s. sNAvELY, or PITTSBURGH, TENNSYLVANIA, AssIGNOR To THE UNION SWITCH a SIGNAL COMPANY, oI swrssvALE, IENNSYLVANIA, A CORPORATION Op imnnsYLvANIa.

ELECTRICAL RELAY.

Application filed April 27, 1921. Serial No. 464,989.

My invention relates to electrical relays. The relay is provided with an electromag- I will describe one form of relay embody-` net which is designated as a whole by the ing my invention, and will then pomt out reference character M. This magnet comthe novel features thereof in av Claim. prises, as usual, two cores 17 of soft iron or 5 In the accompanying drawings, Fig. 1 is a view showing in vertical section one form through suitable holes in the top plate A. of relay embodying my invention. Fig. 2 The lower end of each core is provided with is a bottom View of the relay shown in F 1g. a pole-piece 18 which is integral with the 1, with parts removed to assist in illustrating core and rests against the under surface of s the structure. Fig. 3 is a top planview of the plate A. One manner in which the cores 05 the relay shown in Fig. 1. Fig. 4; is a fra-gmay be attached to the top plate is illustrated mental View of the relay shown in the prein Fig.' 4. Referring to this view, it will be ceding views and illustrating one means for seen that each core has an enlarged portion attaching the magnet cores to the top plate 17a next to the pole-piece 19, and that the upl of the relay. Fig. 5 isa view showing a per end of this enlarged portion is provided portion of the fixed back contactstrueture with screw threads 17h. The top plate A included in the relay shown in the preceding has two holes 19 designed to aeconnnodate views. Figs. 6 and 7 are views showing ya the enlarged portions 17a of the cores, and modification of the means illustrated in Fig. each of these holes is countersunk at the top plate. in the top plate by a sleeve 2() which screws Similar reference characters refer to smnon the threads 17b and the body of which lar parts in each of the several views. enters the countersink 19a, the sleeve being Referring first to Figs. 1, 2 and. 3, the reprovided with a flange which rests on the uplay comprises a top plate A of insulatmg per surface of the plate. After the pole material, preferably porcelain, which suppiece 18 has been drawn tightly against the ports all of the operating parts of the device. top plate by turning the sleeve 20, the parts The armature, contacts, etc. are as usual enmay be locked in place if desired by any closed in a box which is formed by the top suitable device, such as by passing dowel J0 plate A, a base plate 10, and four glass side pins through the sleeves and into the top walls each designated by the reference charplate. y acter 11. Again referring to Figs. 1 and 3, each The base plate 10, as here shown, 1S 0f core 1S is provided with a coil 21 .of the metal such as pressed sheet iron or steel, form-wound type, which is slipped over Square in configuration, and is provldfl the core after the latter" is mounted in the around its entire periphery with an npstandtop plate A. 111g 112mg@ 10a. The Of lill-1S plate SlOpS back-Strap 0f nlagnet M comprises from all four sides toward the center where two Sections 22 and 22e, each .having two other magnetizable material which pass 60 it-is provided with a hole l0h for purpQSeS semi-cylindrical recesses 22 to accommodate 40 O drainage and Ventilation, this hOle blng the uppeI-iends 0f the Cores 17, and the two covered with wire gauze as usual. Attached Sections are clamped together against the tol the under side ofthe plate and integral Cores by a. tap bolt 23 The recesses 22h are therewith are OUI SUppOltiIlg feet 10c, 011e so designed, however, that the two sections at each corner. do not touch each other when clamped in The four glass side walls 11 are located place, thereby insuring heavy pressure be between the Under rim 0f the OP- Plate A tween each section and the two cores 17. and the upper rim 0f the flange 10l 011 the One advantage of this Construction is that it bottom Plate the glass being Separated fIOm 'reduces to a minimum the reluctance of the the plates by means of gaskets 12 and 13 0f joint between the backfstrap and the cores, d0 cork or other suitable material. To hold the and consequently it'msultg m maximum ef- I glassin place, the plates are clamped toficiency of the relay in so far as this part gethel' by OUI machine SCIGWS 16 WhlCh PaSS of the structure is concerned. Another adthrough countersunk holes in the four. corvantage is that it eliminates the necessity for ners of the top plate A and enter tapped threading the cores and backstrapywhen holes in the four corners of the base plate l0. Norway iron is used the threading operation is unsatisfactory because the threads do not cutI clean owing to the fibrous nature .of the material. If' desired, a through bolt and nut construction inay be substituted for the tap bolt 23 to eliminate the tapping'required for'this bolt.

The electromagnet M-controls au armature 24 which, the construction here shown, is mounted in pivot pins 25, 25 supportedby an armaturebracket 26, and which bracket, in turn is attached to the pole-pieces 18 by screws 27. The upwardv movement. of this armature is limited by an adjustable stop 44 which is-mounted in the top plate A, safety core pinsl 45 being provided in*l the'V poleA pieces 18 to prevent actualcontact ofthe armature with these pole-.pieces in the event.

i' tact spring supports, oneof which is pro- .vided for each contact finger of the relay.

This support is made of aninsulating mav structure are as follows: The face of the '.metaltip 32a-works on practically an edge terial, and is preferably a vitreous substance, such as porcelain." This support is substantially Z-shaped as shown in Fig. l, but the two legs are notparallel. One leg Aof the support is attached tothe armature by a screw 29, the support being kept in proper alignment by a pin 30 which is seated- '1n the armature and projects into a slot 3l formed in the support 28. The other or free legof the support-carries a contact spring 32 which is erfectly yflat and is attached to the support by a'screw 33. The shape of the support 28 is such that whentheearmature 24 is horizontal, the contact spring 32- slopes upwardl at an angle of about 10 as shown;

in the rawing. vEach contact spring 32 coacts with one or more fixed contact meme bers as explained'. hereinafter.

I' which .I have shown for attaching it to the of. considerable-importance. The spring 32 a is dat, and is applied to the support 28 with- The contact-spring 32 and the means .armature 24 have certain. features which are out any set. or bend, so that there is little or. no. tendency -for this spring to warp. The4 support 28, bemg of porcelain 'or other vitreous substance, is'not subject to shrinlgage or to distortion. It follows that thecali-V loratio'n of the relay, in so fa'r as the supports-'28and contact springs 32 are con-A cerned,will remain practically without vaj riaton throughout the life of the relay.

' The :free end of'each contact spring- 32 "i -vis provided -with a tip 32l of silver, platif num, orother metal 'which does not reallilly 1S -'.\fparallelingers in Aaccordam'ze with usual 'atamwt' practice, and` the tip will usually be riveted fto theend ofthe contact spring. as shown` 1n 5 graphite member impossible.

important lfeature 1s' that the-co-eilicient of In the form of relay shown herein, each contact spring 32 coacts with a fixed front contact member F when the armature 24 is closed, and with aiixed back Contact member B when the armature is open.

The front contact member F comprises' a bl.ock of graphite 34 mounted in a. terminal lpost 36 which in turn is supported in -the top plate A of the relay. The lower or projecting end of the graphthe ytip engages the edge 34b of the block before thevmovement of the armature is completed, and during the remainder ofA the movement vthe tip slides tothe left l on the.

edge I34th The main advantages of this contact of graphite, so that any wearwhich occurs i due to rubbing and arcingwill reduce the "ridgeof the graphite block, or the high points thereon if any exist, and so will automatically align the contact edge of the graphite with the contact surface l of the spring. This results in 4lowering the electrical resistance of the contact. Owing to the slope. ofthe graphite surfaces, a very 32a engaging with considerable area of .with the block 34. As thearmatur'e closes,

graphite, sov that 'as soon as the seating action hastaken place, further wear is negligible in so far -Ias its effect on the calibration of the relay is concerned, because of the large amount of graphite which would have to be worn away in order to affect 'the operation of spring 32. An important feature of the structure is the fact' that. failure of the armatureto close due to pitting ofthe..

Another friction. o fthe contact is negligible, so that .practically no workis rquired on vthe part coming` friction in the contacts. Furthermore, there isno op-f of the armature in o've portunity forjthe silver tip to lock itself 1n contact withthe graphite member, be-

'c-ause vof the shape of vthis member and the -angle of spring' 32 with'rielationz thereto.

The structure retains theadvanta'ges of the split Vfinger contact, each finger of the tip 32'"maki11g individual engagement with the ege'of the graphite member.

top plate A. The @device here shown for Any suitable mea-nsmay be provided "for locking the terminal post 36 in place lin the accomplishing this purpose comprisesV a washer 38 provided 'with ,screw-threads w ite block 34 is wedge-shaped, as shown in Inn slight amount of` wear results in the silver This structure makes possible the use of a as to prevent vclaires matching those on the post 36. The top plateA is provided with a small recess 39 located close to the hole through which the post passes, and which recess is filled with a suitable material, such as lead. To lock the terminal post in place the washer 38 1s turned down tight against the upper surface of the top plate and a hole is then drilled through this washer and into the lead in the recess -,39. A dowel pin 40 1s thenpassed through the hole and cut off flush with the top surface of the washer 38.

solid terminal post, and at the same time it secures this post in place in such manner tampering with'the same without actually showing signs of tampering or destroying the post. The post may readily be renewed in the shop, however, by drilling outv the dowel pin and' providing a new washer 38. The structure described reno special construction Iof the top plate'A other than the small recess 39 for accommodating the dowel pin 40.

Each back contact B comprises member 35, shaped as shown in Figs. 1 and 5, and attached to a terminal post 41, which passes through the top plate A. The post 41 is provided with ahead 41a which is drilled and tapped to accommodate a machine screw 42', which in turn attaches the contact member 35 to the terminal post. The

a brass contact member 35 is preferably of sheetV brass, provided with a tip 35 of silver or platinum riveted r arranged for engagement with the tip 32 on contact spring 32. o

Referring now to Figs. 6 and 7, I have 'here shown a modification of the structure illustrated in Fig. l4 for mounting the cores 17 of the electromagnet M in the top plate A. In the form shown in Fig. 6 each core 17 is provided with an enlarged neck 17 adjacent the pole-piece 18,

is provided with countersunlr holes 19 to A accommodate these enlarged lneck portions of the cores. Each core isfprovided with acollar 43 of non-magnetizable material, such, for example, as brass, the inside of which is reamed so as to be a pressed or forced iit over the neck portion 17's of the core.v To assemble the structure the cores 17 are inserted in the top plate and the collar 43 pressed into place. The initial position of the collar on the core is shown in Fig. 7, whereas the inal position is shown in Fig. 6. After 'the collars have been pressed into place, it may be desirable to either slightly rivet orspin the upper edge of the neck with `that resulting to the member 35, and' andthe top plate A portion 17, as indicated at 17,'to prevent the collar 43 from rising on the neck piece.

`One advantage of this structure is that due to' the enlarged neck piece 1"(c thereluctance of the magnetic circuit is decreased at the part of this circuit which is not covered by the magnetizing coil`21. This enlargedo neck piece also tends to draw the magneticflux down .to the pole-piece, and hence it decreases the leakage as compared from a core of thin section in the top plate or a broken or threaded section at this point. It follows, therefore, that the structure shown in these views increases the efficiency of the relay. Anothel` advantage of the structure is that the forming of thc'core 17 can be accomplished entirely by grinding. fibrous nature of Norway iron which is generally used for magnet cores, the substitution of grinding for threading and pping, and also the simplicity of assembly due to the present method, considerably cheapens the production of the` relay. Another advantage of the structure is the re inforcing action on the top plate A, as com- Due to the soft and pared with the weakening of this plate when l screws are used for supporting the cores.

I do not in the present application -make any features being disclosed co-pending application, Serial No. 464,988, filed on even date herewith by Clarence S. Snavely and Arthur W. Fisher:

(a) The structure shown for attaching the graphite block 34 to the terminal post 36.

(b) The-structure of the relay box-comprising the base plate 10 and the glass wallsll.

(c) The structure of the back strap for 'n electromagnet M.

Althoughl I' have herein shown and described only one my invention, it is understood that various changes and modifications may' be made therein within the scope ofthe appended claim without departing from the spirit and scope of my invention.

claim for the following features, these' and claimed in a,

form of relay embodyingv lor Having thus described my4 invention, what I claimis:

A relay comprising a movable armature, a substantially Z-shaped member of porcelain one leg of which is attached to said armature, afiexible contact spring attached directly to the other leg of said insulating member, and a fixed contact element coacting with said spring.

In testimony whereof I affix my signature.

, CLARENCE S. SNAVELY. 

